JP3463393B2 - Reversible thermosensitive recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information medium comprising a temperature-dependent reversible thermosensitive recording layer and a hologram image superimposed on each other.
The present invention relates to a reversible thermosensitive recording medium that can be used as a seal or a label, and is particularly excellent in the design and tamperproof property of a hologram.

[0002]

2. Description of the Related Art Conventionally, rewritable thermosensitive recording media have been disclosed in JP-A-55-154198 and US Pat.
No. 268413, a thermoplastic resin such as polyvinyl chloride and a thermosensitive recording layer mainly composed of an organic low molecular weight substance such as a higher fatty acid dispersed in the thermoplastic resin are provided on a support. There is something.

This heat-sensitive recording layer has a light absorption property (light scattering property) that reversibly changes depending on temperature.
That is, the heat-sensitive recording material constituting the heat-sensitive recording layer has two state transition temperatures T at temperatures higher than the specific temperature T ₀ near room temperature.
₁ and T ₂ (where T ₁ <T ₂ ) and the thermal recording layer is T
_When heated to ₂ or more and held and then cooled to T ₀ or less, the thermosensitive recording material becomes clouded, light scattering increases, and the maximum light shielding state is obtained. On the other hand, when the heat-sensitive recording layer in the cloudy state is heated to T ₁ or more and less than T ₂ , held, and then cooled to T ₀ or less, its light scattering property is reduced and becomes a transparent state. Therefore, under the temperature condition of T ₀ or less, the maximum light-shielding state and the transparent state of the thermosensitive recording layer can be stably maintained, respectively, and these states can be reversibly changed. By setting the state, the visible information recorded can be used in a rewritable state and can be used as a heat-sensitive recording medium due to the difference from the other state.

Further, only by controlling the thermal energy,
Reversible thermosensitive recording materials that chemically develop and decolor are disclosed in JP-A-2-188293, JP-A-2-188294, International Publication No. WO90 / 11898, and the like, which are referred to as leuco compounds. A reversible heat-sensitive recording material mainly composed of a binder and a color-developing / reducing agent that develops / decolorizes a leuco compound by controlling heat energy, and is provided on a support as a heat-sensitive recording layer. . This heat-sensitive recording material uses a compound having both properties of a group having a color-developing effect (acidic component) and a group having a color-reducing effect (component made of a base) as a color-developing and color-reducing agent to develop color by controlling applied heat It erases color. With this heat-sensitive recording material, it is possible to hold a stable image with time in an environment of daily life. The color developing and decoloring characteristics and the image stability are largely due to the chemical structure of the developer and decolorizer in the material.

More recently, decorations have been made on media such as stock certificates, gift certificates, checks, lottery tickets, boarding tickets, commuter tickets, and other media such as ID cards, credit cards, cash cards, and prepaid cards. For the purpose of preventing forgery and falsification, a hologram is formed by using a seal, a label or a transfer foil having a relief hologram. It is said that these holograms can be visually checked, and the authenticity of the holograms can be easily determined, and that the hologram manufacturing itself requires a technique and a device, which has been the basis for preventing fraud.

As a method of adding the hologram to the medium, a transfer foil is widely used as a hologram forming means because of its low cost, thinness, and tampering resistance. Such a hologram transfer foil is disclosed in JP-A-61-190.
No. 370, a release film, a resin layer having a surface relief hologram formed thereon, a metal reflection layer, and a heat-sensitive adhesive layer are sequentially formed on one surface of a support film,
The heat-sensitive adhesive layer is brought into close contact with the surface of the base material, and the transfer portion is heated and pressed to transfer and form a predetermined hologram image. When there is a printed pattern on the base material, by using a transparent hologram that uses a transparent metal reflection layer, the hologram image and the printed pattern can be displayed without affecting the appearance of the printed pattern on the base material by the hologram. It is possible to see by overlapping. Furthermore, a print-integrated hologram in which a hologram image and a print pattern are superposed has been proposed and is used as a seal, a label, a transfer foil, or the like.

[0007] At present, as an alternative technique to the discrimination such as hologram using only visual inspection, for example, Japanese Patent Laid-Open No. 3-21109.
As described in Japanese Patent Publication No. 6, there is an information recording method in which information is formed by changing the spatial frequency of the diffraction grating and the direction of the diffraction grating, and the information is read by the reflection direction of laser light or the like.

[0008]

However, the hologram as described above is forged or counterfeited simply due to the peculiarity of the stereoscopic image of the hologram and the difficulty of the hologram transfer foil manufacturing process.
Although it is a measure to prevent unauthorized alteration such as alteration and tampering, a forgery technology that prints a regular hologram image pattern with transparent ink on a metal foil and makes it look like a hologram image at first glance has also appeared, and the hologram itself is illegal. Attempts have been made to duplicate it, and it cannot be said that this is a reliable fraud prevention measure that makes it possible to identify fraudulent behavior at first glance. Further, even with a diffraction grating that accurately and mechanically makes a genuine / counterfeit determination, there is a problem that it is difficult to make a genuine / counterfeit determination of a similar counterfeit product when a visual determination is required.

Further, security information or the like for preventing fraud of a card or the like may be concentrated on a specific portion of the card for identification, or may be arranged on the card as an information form that cannot be easily identified by visual inspection or the like. Although the measures are taken, there is still no countermeasure against fraud by combining with a hologram, and at present, the hologram portion of the card as described above only provides information of the hologram.

Therefore, according to the present invention, a reversible thermosensitive recording layer is formed under a three-dimensional hologram image so that visible information can be rewritten and displayed so that the authenticity of the medium and the transfer material can be determined while maintaining the design. It is an object of the present invention to provide a reversible thermosensitive recording medium capable of easily performing.

[0011]

The present invention has been made to achieve the above object, and the invention according to claim 1 is to provide a reflective thin film layer, a reversible thermosensitive recording layer, and A reversible thermosensitive recording characterized in that a hologram forming layer having a minute uneven shape and a hologram layer composed of a transparent thin film layer having a refractive index different from that of the hologram forming layer and a protective layer are sequentially laminated on the minute uneven surface. It is a medium.

A second aspect of the present invention is a hologram layer comprising a peeling protection layer on a support, a hologram forming layer having fine irregularities and a transparent thin film layer having a refractive index different from that of the hologram forming layer on the fine irregularities. A reversible thermosensitive recording medium comprising a reversible thermosensitive recording layer, a reflective thin film layer, and an adhesive layer, which are sequentially provided and can be peeled from a support.

The invention of claim 3 is the reversible thermosensitive recording medium according to claim 1 or 2, wherein the reversible thermosensitive recording layer comprises:
A reversible thermosensitive recording medium comprising a resin base material and an organic low molecular weight substance dispersed in the resin base material as a main component, and the transparency thereof reversibly changes depending on temperature.

According to a fourth aspect of the present invention, in the reversible thermosensitive recording medium according to the first or second aspect, the reversible thermosensitive recording layer comprises:
Characterized by a leuco compound, a color-developing / reducing agent that thermally reacts with the leuco compound to develop or reduce color, and a binder as main components, and reversibly develop and decolor by controlling heat energy. It is a reversible thermosensitive recording medium.

According to a fifth aspect of the present invention, in the reversible thermosensitive recording medium according to the first or second aspect, a colored layer is provided between the reflective thin film layer and the reversible thermosensitive recording layer. It is a reversible thermal recording transfer material.

The invention of claim 6 is the reversible thermosensitive recording medium according to claim 1, characterized in that an adhesive layer is provided on the surface in contact with the adherend. .

[0017]

According to the reversible thermosensitive recording medium of the present invention, visible information is recorded on the reversible thermosensitive recording layer located under the hologram image in a state of being superposed on the hologram image. The visible information can be rewritten without affecting the hologram image.

[0018]

The present invention will be described in detail below with reference to the drawings. 1 is a sectional view showing an embodiment of the reversible thermosensitive recording medium of the present invention, FIG. 2 is a sectional view showing another embodiment of the reversible thermosensitive recording medium of the present invention, and FIG. 3 is a second embodiment. 4 is a sectional view showing an embodiment of the reversible thermosensitive recording medium of the invention of FIG.
FIG. 6 is a sectional view showing another embodiment of the reversible thermosensitive recording medium of the second invention.

FIG. 1 shows a layer structure of a reversible thermosensitive recording medium 1 of the present invention, which comprises a substrate 2, a reflective thin film layer 3, a reversible thermosensitive recording layer 4, a hologram forming layer 5 having a hologram image, and A hologram layer 7 made of a transparent thin film layer 6 having a different refractive index from the hologram forming layer 5, and a protective layer 8 are sequentially provided. The hologram forming layer 5 and the transparent thin film layer 6 forming the hologram layer 7 may be reversed in order, or the reflective thin film layer and the reversible thermosensitive recording layer may be adhered to each other via an adhesive layer. Further, the reversible thermosensitive recording medium 1 is, for example, in the case of a card-shaped information medium, on the other surface of the base material 2 such as a printing layer or a magnetic recording layer formed of character information or a design depending on its application. An optional information recording means may be provided, or when it is used for a seal or a label, an adhesive layer made of a heat sensitive adhesive or a pressure sensitive adhesive (adhesive) may be provided on the other surface of the substrate 2.

The hologram image used for the hologram layer 7 can be an image according to a conventionally known hologram technique. For example, as a hologram, these images are formed on the hologram forming layer 5 as a white light reproducing hologram including a relief hologram, a monochromatic light reproducing hologram including a Fresnel type or a Fourier transform type, and the hologram forming layer is formed on the relief forming surface. Has a refractive index different from 5,
Moreover, a high hologram effect can be obtained by providing the reflective thin film layer 6 having transparency. The hologram may be a diffraction grating having specific information in addition to images such as characters and images. The diffraction grating changes the spatial frequency, the direction of the diffraction grating, or a combination thereof to record information. Further, the hologram layer 7 can be a volume hologram such as a Lippmann hologram, and can be arbitrarily selected according to the application. This Lippmann hologram records a hologram image by forming portions having different densities, that is, portions having different refractive indexes in the layer. Recording materials include silver salt emulsion, gelatin emulsion, photopolymerizable resin,
A photosensitive material such as a photocrosslinkable resin is used. This is subjected to exposure-development-fixing treatment to change the refractive index in the layer and a hologram image is recorded. In addition, the hologram forming layer 5
The hologram image of does not have to be provided on the entire surface, and the hologram image can be formed on a part thereof. The hologram forming layer itself can also be partially provided on the base material 2 according to the size of the hologram image. The base material 2 may be omitted and the hologram forming layer 5 may be used as a base material. According to this, the layer thickness of the medium can be reduced,
Suitable for applications such as stickers or labels.

The layers constituting the reversible thermosensitive recording medium of the present invention will be described below. The base material 2 has a role as a support, and includes, for example, paper, synthetic paper, polyvinyl chloride, polyester such as polyethylene terephthalate (PET),
Polycarbinate, polymethylmethacrylate, polystyrene, etc. that have been used for prepaid cards, cash cards, credit cards, admission tickets, pass tickets, gift certificates, etc. and certificates, seals, and labels. If so, it is not particularly limited. A combination of different materials may be used, or a single-layer or multi-layer structure may be used, or the physical properties such as transparency, semitransparency, opacity, strength, rigidity, and hiding property may be appropriately selected according to the application. In addition, if the base material 2 is colored so as to improve the visibility of the thermosensitive recording layer and the hologram forming layer,
It is also possible to omit the reflective thin film layer 3. Further, for example, there is a base material having reflectivity in the case of a rainbow hologram and a dark-colored base material (black as an example) in the case of a Lippmann hologram.

The reflective thin film layer 3 is provided mainly for obtaining the visibility of the reversible thermosensitive recording layer 4. In the case of a cloudy white-transparent reversible thermosensitive recording layer, it exhibits light reflectivity. A thin film reflective layer made of a metal material is preferable. For example, there are aluminum, tin, silver, copper, magnesium, chromium, nickel and the like, and alloys or compounds thereof. As a means for forming these into a thin film, known methods such as vacuum vapor deposition method, reactive vacuum vapor deposition method, sputtering method, reactive sputtering method, ion plating method, and electroplating method can be used. Is 0.03 to 0.08 μm. The metal reflection layer 3 can be omitted depending on the characteristics of the base material 2.

Rewritable reversible thermosensitive recording layer 4
Is that the transparency changes reversibly depending on the temperature,
The visible information is recorded by partially changing the information.
For example, as described above, the main component is the resin base material and the organic low molecular weight substance dispersed therein, and the heat-sensitive recording material has two state transition temperatures T ₁ and T _{2 at a} temperature higher than the specific temperature T ₀ near room temperature. (Provided that T ₁ <T ₂ ), and when the thermosensitive recording layer is heated to T ₂ or higher and held and then cooled to T ₀ or lower, the thermosensitive recording material becomes cloudy (light due to a change in the crystalline state of organic small molecules). Scattering), and the light-scattering property is increased to reach the maximum light-shielding state. On the other hand, when the heat-sensitive recording layer in the cloudy state is heated to T ₁ or more and less than T ₂ , and held and then cooled to T ₀ or less, its light scattering property is reduced (light is transmitted) and it becomes transparent. As described above, under the temperature condition of T ₀ or less, the maximum light-shielding state and the transparent state of the thermosensitive recording layer can be stably maintained, respectively, and these states can be reversibly changed. Is set to the base state, the visible information recorded due to the difference from the other state can be held in a rewritable state.

The resin base material has a refractive index close to that of organic low molecules, is incompatible, has excellent mechanical strength, has film forming ability, and has excellent transparency, and is a thermosetting resin or thermoplastic resin. Is used. Specific examples include polyester resins such as saturated copolymerized polyesters; polyvinyl chloride resins; vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-vinyl alcohol copolymers, vinyl chloride-acrylate copolymers, and other vinyl chlorides. Copolymers; Polyurethane resins; Polycarbonate resins; Polyvinylidene chloride resins; Vinylidene chloride-vinyl chloride copolymers, vinylidene chloride copolymers such as vinylidene chloride-acrylonitrile copolymers; Rubber systems such as natural rubber and synthetic rubber; Polyamides There are resins; silicone resins; polyacrylate or polymethacrylate resins, or copolymers thereof; polyethylene resins and the like, and these are used alone or as a mixture of two or more thereof.

The organic low molecule dispersed in the resin base material includes a fatty acid or a fatty acid derivative, or an alicyclic organic acid. More specifically, a saturated or unsaturated mono- or dicarboxylic acid, or an ester thereof, Some include amides. Specific examples of the saturated fatty acid, undecanoic acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nanodecanoic acid, arachidic acid, behenic acid, lignoceric acid,
Cerotic acid, montanic acid, melissic acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid,
1,9-Nonamerylene dicarboxylic acid, 1,10-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-
Examples thereof include cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Specific examples of unsaturated fatty acids include oleic acid, linoleic acid, sorbic acid and stearolic acid. It is to be noted that the present invention is not limited to the above-mentioned ones, and it is also possible to use a plurality of the organic low-molecular substances in combination. Further, a coating liquid in which an organic low molecule and a resin base material are mixed is prepared by dissolving the binder in a coating liquid obtained by uniformly dispersing or dissolving the above leuco compound and amphoteric compound in water or an organic solvent, and dispersing the binder as necessary. Agent, antifoaming agent, thickening agent and other liquid modifiers are applied by a known coating method such as bar coating, blade coating, air knife coating, gravure coating or roll coating, and dried. Then, the thermosensitive recording layer 4 is formed.

Further, the rewritable reversible thermosensitive recording layer 4
As another heat-sensitive recording material used in the above, a reversible heat-sensitive recording material containing a leuco compound, a color-developing / color-reducing agent for developing / decoloring the leuco compound by controlling heat energy, and a binder as main components can be used. Examples of the leuco compound include fluorene compounds, fluorane compounds, phthalide derivatives and the like. Specific examples include crystal violet lactone, 3-indolino-3-p-dimethylaminophenyl-6-dimethylaminophthalide, 3
-Diethylamino-7-chlorofluorane, 2- (2-
Fluorophenylamino) -6-diethylaminofluorane, 2- (2-fluorophenylamino) -6-di-
n-Butylaminofluorane, 3-diethylamino-7
-Cyclohexylaminofluorane, 3-diethylamino-5-methyl-7-t-butylfluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3
-Diethylamino-6-methyl-7-p-butylanilinofluorane, 3-cyclohexylamino-6-chlorofluorane, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) -fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane, 3-N-methylcyclohexylamino-6-methyl-7-anilinofluorane, 3-N-ethyl Mention may be made of pentylamino-6-methyl-7-anilinofluorane and the like.

The amphoteric compound acting as a color-developing agent for the leuco compound has at least one of a phenolic hydroxyl group and a carboxyl group, and has an amino group as a functional group or as a part of a salt compound. is there. As a color-developing agent, for example, a compound having both an acidic component consisting of a phenolic hydroxyl group or a carboxyl group and a basic group consisting of an amino group, which becomes acidic or basic due to the difference in thermal energy and develops a leuco compound (coloring). ) ・ Some have color reduction (erasing). The basic group may be present as a functional group or as a part of chloride. Examples of the developer / color-reducing agent having an amino group as a functional group include aminobenzoic acid, hydroxyaminobenzoic acid, aminophenols, aminonaphthoic acids, nicotinic acids and the like. Specific examples include p-aminobenzoic acid, m-aminobenzoic acid, o-aminobenzoic acid,
4-amino-3-methylbenzoic acid, 3-amino-4-methylbenzoic acid, 2-amino-5-ethylbenzoic acid, 3-
Amino-4-butylbenzoic acid, 4-amino-3-methoxybenzoic acid, 3-amino-4-ethoxybenzoic acid, 2-
Amino-5-chlorobenzoic acid, 4-amino-3-bromobenzoic acid, 2-amino-4-nitrobenzoic acid, 4-amino-3-nitrobenzoic acid, 3-amino-4-nitrilebenzoic acid, aminosalicylic acid , Diaminobenzoic acid, 2-methyl-5-aminonaphthoic acid, 3-ethyl-4-aminonaphthoic acid, nicotinic acid, isonicotinic acid, 2-methylnicotinic acid, 6-chloronicotinic acid and the like.

The compound having a basic group as a part of the chloride is a salt or complex salt of a compound having a phenolic hydroxyl group or a carboxyl group and a compound having an amino group, such as hydroxybenzoic acid and hydroxysalicylic acid. Examples thereof include salts or complex salts of acids such as gallic acids, gallic acids, and bisphenolacetic acid with aliphatic amines, phenylalkylamines, trialkylamines, and the like. As specific examples, p-hydroxybenzoic acid-alkylamine salt, p-hydroxybenzoic acid-phenylalkylamine salt, m-hydroxybenzoic acid-alkylamine salt, 2,
4-dihydroxybenzoic acid-alkylamine salt, 4,5
-Dihydroxybenzoic acid-tolylalkylamine salt, p
-Hydroxybenzoic acid methyl-alkylamine salt, p-
Hydroxybenzoic acid stearyl-alkylamine salt, gallic acid-alkylamine salt, gallic acid dodecyl-alkylamine salt, gallic acid stearyl-alkylamine salt,
Examples thereof include bisphenolacetic acid-alkylamine salt, bisphenolacetic acid stearyl-alkylamine salt, and bisphenolacetic acid octyl-alkylamine salt.

Further, these color-developing / reducing agents are disclosed in JP-A-2-188293 and JP-A-2-188293 filed by the present inventors in advance.
No. 188294, International Public Law No. WO90 / 118
Materials described in No. 98 and the like can also be mentioned. Also, two or more kinds may be used at the same time.

As the binder, a polymer resin soluble in water or an organic solvent can be used.
Specific examples of such polymer resins include polyvinyl alcohol, methyl cellulose, cellulose acetate, methoxy cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, gelatin, casein, starches, sodium polyacrylate, and styrene-maleic acid copolymer. Water-soluble polymer such as polymer, polystyrene, polyvinyl chloride, linear saturated polyester, homo- or copolymer of methacrylic resin such as polymethylmethacrylate or polyethylmethacrylate, polyurethane, polybutyral, nitrocellulose, ethylcellulose , Epoxy resin, acrylic resin, polyester,
Solvent-soluble polymers such as paraffin wax, polyethylene wax, carnauba wax, microcrystalline wax, stearic acid amide, and rubbers can be used. The above leuco compound, the binder is dissolved in a coating liquid obtained by uniformly dispersing or dissolving the amphoteric compound in water or an organic solvent, and if necessary, a liquidity improving agent such as a dispersant, a defoaming agent, and a thickener. The coating liquid added is bar coat, blade coat, air knife coat, gravure coat,
The thermosensitive recording layer 4 is formed by coating and drying by a known coating method such as roll coating. The rewritable thermosensitive recording layer 4 preferably has a layer thickness of about 3 to 20 μm.

Further, the hologram layer 7 comprises a hologram forming layer 5 and a transparent thin film layer 6. A hologram image is formed on at least a part of the hologram forming layer 5. In the case of a relief hologram, a relief forming surface 10 (recording interference fringes with unevenness) representing a hologram image is formed on a resin, and the resin material is a thermoplastic resin such as polyvinyl chloride, acrylic, polystyrene, or polycarbonate. Unsaturated polyester, melamine, epoxy, urethane, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, triazine acrylate , A material using a thermosetting resin such as a nitrocellulose-based resin or cellulose acetate, or a mixture thereof can be used.

The transparent thin film layer 6 is made of the materials shown in Table 1.
To form a hologram on the relief forming surface 10.
A thin film layer having a refractive index different from that of the layer 5 and showing transparency is formed.
By providing the angle range that can reproduce the hologram image.
In the enclosure, the thin film layer has the maximum light reflectance and
A reproducible corner of the hologram image that acts as a program
Outside the range, the image on the substrate side is seen through as a simple transparent film
In particular, the reflected light from the thin film layer and the thin film layer
The reflected light at the interface with the program forming layer, as well as the thin film layer and
Reflection occurring at the interface with the program forming layer is multiple in the thin film layer.
Higher hologram effect due to reflection
You can The transparent thin film layer 6 can be formed by known means.
Certain vacuum deposition methods, reactive vacuum deposition methods, sputtering
Method, reactive sputtering method, ion plating
Method, electroplating method or the like can be used, and the layer thickness is 0.
It is from 03 to 0.08 μm. Furthermore, since it is listed in Table 1,
The hologram forming layer 5 (for example, the refractive index n =
It is preferable that the refractive index is higher than 1.3 to 1.3).
Good Other than Table 1, for example, Bi₂O₃, CaO / Si
O ₂Etc. In addition, the hologram that forms the hologram layer 7
Which of the ram forming layer 5 and the permeable thin film layer 6 is the base material 2 side
May be.

[0033]

[Table 1]

The protective layer 8 is provided in order to protect the layers located underneath, and may be transparent enough to prevent the visual recognition and detection of hologram images and visible information. Well, for example, known synthetic resins such as acrylic resin, urethane resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, melamine resin, epoxy resin, polystyrene resin, or natural resin can be used. Further, as an additive for improving resistance based on ultraviolet ray or thermosetting resin, a curing agent such as isocyanate, waxes such as polyethylene wax and carnauba wax, extender pigments such as calcium carbonate, silica and alumina, silicone oils and fats, etc. Oils and fats can be used.

In the reversible thermosensitive recording medium 1 of the present invention having the above-mentioned structure, the reflective thin film layer 3, the reversible thermosensitive recording layer 4, the hologram forming layer 5, the transmissive reflective layer 6 and the protective layer are formed on the substrate 2. The hologram image formed by the hologram forming layer 6 is visually observed from the front of the reversible thermosensitive recording medium 1. Recording of visible information on the rewritable heat-sensitive recording layer 5 is carried out by reversible heat-sensing by partially heating the medium from above the hologram forming layer 6 with a heating means (not shown) such as a thermal head according to the pattern of visible information. Recording layer 4
Can be partially heated to bring the heat-sensitive recording layer into the maximum light-shielding state or the transparent state. Then, by holding each of them stably and setting one of the states to the base state, the recorded visible information can be read through the hologram image of the hologram forming layer 6 due to the optical difference from the other state. it can. In addition, information is rewritten by reversibly changing these states. When rewriting, information is erased by heating the information recording surface with a heating means (not shown) such as a hot roll, a hot plate, or a thermal head, and setting the entire light-shielding state or the transparent state. After that, the visible information is recorded by using the heating printing means in the same manner.

Further, as shown in the reversible thermosensitive recording medium 11 of FIG. 2, a colored layer 9 is provided between the reflective thin film layer 3 and the reversible thermosensitive recording layer 4 to improve the visibility of the hologram image and the visible information. The design effect can also be increased. For the colored layer 9, for example, an acrylic resin, a styrene resin, a polyester resin, a vinyl resin, or the like is used as a binder, and a dye or pigment of a desired color is dispersed therein.

Although not shown, when the reversible thermosensitive recording medium of the present invention is used as a seal or a label, a thermosensitive adhesive or a pressure sensitive adhesive (adhesive) is provided on the back surface of the substrate 2 as an adhesive layer. For this adhesive layer, for example, vinyl chloride type, vinyl acetate type, acrylic type, polyester type, etc. are used.

Next, as shown in FIG. 3, the reversible thermosensitive recording medium 21 according to the second aspect of the present invention has a transparent protective layer 18, a hologram forming layer 15 and a transparent layer having a refractive index different from that of the support 12, as shown in FIG. A hologram layer 17 including a reflection layer 16 and a hologram forming layer 15, a reversible thermosensitive recording layer 14, a reflective thin film layer 13, and an adhesive layer 22 are sequentially provided. The hologram forming layer 15 and the transparent thin film layer 16 forming the hologram layer 17 may be reversed in order, or the reflective thin film layer and the reversible thermosensitive recording layer may be adhered to each other via an adhesive layer. Further, the hologram forming layer 15, the rewritable thermosensitive recording layer 14, the transparent reflecting layer 16 having a different refractive index from the hologram forming layer 15, and the reflective thin film layer 13 are the same as those of the reversible thermosensitive recording medium 1 of the first invention described above. It is the same as the same constituent layer. Hereinafter, different configurations will be described.

The support 12 is preferably made of, for example, a polyethylene terephthalate film or a polyethylene naphthalate film having tensile strength and heat resistance. The peelable protective layer 18 peels and transfers the transfer layer 20 including the hologram forming layer 15 and below from the support 12 to the adherend, and is, for example, a mixture of a thermoplastic resin and a friction-resistant agent. Polymethacrylate and epoxy resin, and as the anti-friction agent, natural wax such as Teflon powder and polyethylene powder, synthetic wax, metal salt of higher fatty acid and the like are used. In particular, the peelable protective layer 18 after peeling serves as a protective layer for the hologram forming layer 15. The adhesive layer 22 is a heat-sensitive adhesive or a pressure-sensitive adhesive (adhesive) formed by adhering the transfer layer 20 to the adherend,
For example, vinyl chloride type, vinyl acetate type, acrylic type, polyester type and the like are used.

The reversible thermosensitive recording medium 21 is superposed on a transfer material (not shown) and heated from the support 12 side.
By applying pressure or pressure, the transfer layer 20 is adhered to the transfer material,
After that, the support 12 is peeled off to form a reversible thermosensitive recording medium (not shown) in which the reversible thermosensitive recording layer 14 and the hologram forming layer 15 are superposed on the transfer material. From the front of the reversible thermosensitive recording medium, the hologram image formed by the hologram forming layer 15 is visually observed. To record visible information on the reversible thermosensitive recording layer, as described above, the heating means (not shown), for example, a thermal head is partially heated from above the hologram forming layer 15 according to the pattern of the visible information to reversible thermosensitive recording. The layer 14 is partially heated so that the heat-sensitive recording layer can be in the maximum light-shielded state or the transparent state. By stably holding each of them and setting one of the states to the base state, the visible information recorded can be read through the hologram image of the hologram forming layer 15 due to the optical difference from the other state. In addition, information is rewritten by reversibly changing these states. When rewriting, information is erased by heating the information recording surface with a heating means (not shown) such as a hot roll, a hot plate, or a thermal head, and setting the entire light-shielding state or the transparent state. Then, the visible information is recorded using the heating means in the same manner.

As described above, the reversible thermosensitive recording layer and the hologram forming layer are simply superposed on various objects as long as they can be transferred in addition to being partially provided on the material to be transferred. A reversible thermosensitive recording medium can be formed. Further, the transfer layer 20 of the reversible thermosensitive recording medium 21 may be cut into a predetermined transfer pattern so as to facilitate transfer.

Further, as shown in the reversible thermosensitive recording medium 31 of FIG. 4, a coloring layer 19 is provided between the reflective thin film layer 13 and the reversible thermosensitive recording layer 14 to improve the visibility of the hologram image and the visible information. The design effect can also be increased. This colored layer 19 is made of, for example, acrylic resin, styrene resin,
A polyester resin, a vinyl resin, or the like is used as a binder, and a dye or pigment of a desired color is dispersed therein.

Further specific examples will be described in detail. <Example 1> As shown in FIG. 1, a base material 2 made of a polyethylene terephthalate (PET) resin sheet (thickness: 25 μm), a reflective thin film layer 3 made of an aluminum vapor deposition film (thickness: 500Å), and the following (1): The reversible thermosensitive recording layer 4 (layer thickness: 10 μm) having the composition described above and the hologram forming layer 5 having the composition described in (2) below are provided, and the relief forming surface 10 having unevenness as interference fringes of the hologram image is formed on the hologram forming layer 5. Was embossed. Furthermore, zinc sulfide (Zn
S) of the transparent reflective layer 6 (layer thickness 500
Å) and a protective layer 7 made of an ultraviolet curable resin were respectively provided to obtain a reversible thermosensitive recording medium 1. (1) Composition of reversible thermosensitive recording layer Stearic acid 7 parts by weight Sebacic acid 2 parts by weight Vinyl chloride-vinyl acetate copolymer resin 6 parts by weight Tetrahydrofuran 30 parts by weight Toluene 20 parts by weight (2) Composition of hologram forming layer Urethane resin 20 parts by weight Curing agent 2 parts by weight Methyl ethyl ketone 39 parts by weight Toluene 39 parts by weight

When the obtained reversible thermosensitive recording medium 1 was observed from the front, a hologram image of the hologram forming layer was visually recognized. Furthermore, a thermal head (0.3 mJ / do
When information was written by heating from above the hologram forming layer 6 using t), opaque information could be recorded at the irradiated portion, and this visible information was observed in superposition with the hologram image. When the entire information recording surface of the reversible thermosensitive recording medium 1 is heated and cooled by any one of a heat roll, a heat plate and a thermal head (surface temperature 80 ° C.), the cloudy portion becomes transparent and the visible information Was erased, and only the hologram image was observed from the outside. Then, when the visible information was recorded again in the same manner, it was confirmed that the repeated recording / erasing of the visible information did not affect the hologram image.

<Example 2> Further, between the reflective thin film layer 3 and the reversible thermosensitive recording layer 4 of the reversible thermosensitive recording medium of Example 1, for example, a yellow colored layer 9 (layer thickness 2 μm) made of a dye or a pigment.
m) is provided. As a result, it was confirmed that the visibility of the hologram image and the visible information of the reversible thermosensitive recording layer and the design effect were improved.

Example 3 Next, as shown in FIG. 3, a polyethylene terephthalate (PET) resin sheet (thickness 2
The peelable protective layer 18 made of polymethylmethacrylate and the hologram forming layer 15 made of the composition of (2) above are provided on the support 12 made of 5 μm), and the hologram forming layer 15 has unevenness as interference fringes of the hologram image. The relief forming surface 10 was embossed. Furthermore, zinc sulfide (Zn
S) is formed on the transparent reflective layer 16 (layer thickness 500 by vacuum deposition).
Å), the reversible thermosensitive recording layer 14 having the composition of (1) above
(Layer thickness 10 μm), aluminum vapor deposition film (thickness 500
A reversible thermosensitive recording medium was obtained by respectively providing a reflective thin film layer 13 made of Å) and an adhesive layer 22 made of a mixture of an ultraviolet curable resin and vinyl chloride acetate resin.

The reversible thermosensitive recording medium 21 is brought into close contact with an arbitrary substrate (for example, vinyl chloride sheet), and is adhered by heating and pressing from the back surface thereof, and then the support 1
2 was peeled off to form a reversible thermosensitive recording medium.

When this reversible thermosensitive recording medium was observed from the front, a hologram image of the hologram forming layer was visually recognized. Furthermore, when information was written by heating from above the hologram forming layer 15 using a thermal head (0.3 mJ / dot), cloudy information could be recorded at the irradiated location, and this visible information was superimposed on the hologram image. Was observed. When the entire information recording surface of the reversible thermosensitive recording medium 1 is heated and cooled by any one of a heat roll, a heat plate and a thermal head (surface temperature 80 ° C.), the cloudy portion becomes transparent and the visible information Was erased, and only the hologram image was observed from the outside. Then, when the visible information was recorded again in the same manner, it was confirmed that the repeated recording / erasing of the visible information did not affect the hologram image.

<Example 4> Further, between the reflective thin film layer 13 and the reversible thermosensitive recording layer 14 of the reversible thermosensitive recording medium of Example 2, for example, a yellow colored layer 19 (layer thickness 2 μm) made of a dye or a pigment. ) Is provided. As a result, it was confirmed that the visibility of the hologram image and the visible information of the reversible thermosensitive recording layer and the design effect were improved.

[0050]

In the reversible thermosensitive recording medium of the present invention, a hologram forming layer having a hologram image and a rewritable thermosensitive recording layer are laminated, and visible information is written from above the hologram forming layer to below the hologram forming layer. By checking the hologram image and the rewritable visible information in a superposed state, the hologram image acts as a decoration of the visible image, and if the design effect improperly alters or forges, the observer sees the hologram image. Since attention is paid to the portion, a slight difference in the visible information becomes conspicuous, which leads to the discovery of fraud. Further, the reversible thermosensitive recording layer can arbitrarily record and erase visible information without affecting the hologram image, and can be widely used as an information recording medium.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a reversible thermosensitive recording medium of the present invention.

FIG. 2 is a sectional view showing another embodiment of the reversible thermosensitive recording medium of the present invention.

FIG. 3 is a sectional view showing an embodiment of the reversible thermosensitive recording medium of the second invention of the present invention.

FIG. 4 is a sectional view showing another embodiment of the reversible thermosensitive recording medium of the second invention of the present invention.

[Explanation of symbols]

1, 11, 21, 31 Reversible thermosensitive recording medium 2 base materials 3,13 Reflective thin film layer 4,14 Reversible thermosensitive recording layer 5, 15 Hologram forming layer 6, 16 Transparent thin film layer 7,17 Hologram layer 8 protective layer 9, 19 Coloring layer 10 Relief forming surface 12 Support 18 Peelable protective layer 20 Transfer layer 22 Adhesive layer

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI G03H 1/18 B41M 5/18 B G06K 19/06 109 19/10 5/26 102 G06K 19/00 D R (56) References JP-A-4-73193 (JP, A) JP-A-5-201182 (JP, A) JP-A-8-187979 (JP, A) JP-A-7-186577 (JP, A) Actual development Sho-62-184576 (JP, U) Actual development Sho 61-272772 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/28-5/34 B41M 5/36 B42D 15/10 501 G03H 1/00-5/00

Claims (6)

(57) [Claims] 1. A reflective thin film layer, a reversible heat-sensitive recording layer, a hologram forming layer having minute irregularities and a transparent thin film layer having a refractive index different from that of the hologram forming layer on the minute irregularities surface on the substrate. A reversible thermosensitive recording medium comprising a hologram layer and a protective layer which are sequentially laminated. 2. A reversible thermosensitive recording layer comprising a peeling protection layer on a support, a hologram forming layer having minute irregularities, and a transparent thin film layer having a refractive index different from that of the hologram forming layer on the minute irregularities surface. A reversible thermosensitive recording medium comprising a layer, a reflective thin film layer, and an adhesive layer, which are sequentially provided and which can be peeled from the support. 3. The reversible thermosensitive recording layer contains a resin base material and an organic low molecular weight substance dispersed in the resin base material as main components, and its transparency reversibly changes depending on temperature. The reversible thermosensitive recording medium according to claim 1 or 2, wherein 4. The reversible thermosensitive recording layer contains a leuco compound, a color-developing / reducing agent that thermally reacts with the leuco compound to develop or reduce color, and a binder as main components, and controls thermal energy to The reversible thermosensitive recording medium according to claim 1 or 2, which reversibly develops and erases color. 5. The reversible thermosensitive recording medium according to claim 1, wherein a colored layer is provided between the reflective thin film layer and the reversible thermosensitive recording layer. 6. The reversible thermosensitive recording medium according to claim 1, wherein an adhesive layer is provided on the surface in contact with the adherend.